public int AddPromise(PromiseTask promise)
{
if (lastId < 0)
{
throw new IndexOutOfRangeException(nameof(lastId));
}
promises[lastId] = promise;
return(lastId++);
}
protected override void DoAsyncWork(CefV8Context ctx, PromiseTask promiseTask)
{
int promiseId = pendingPromises.AddPromise(promiseTask);
var browser = ctx.GetBrowser();
var frame = browser.GetMainFrame();
var msg = CefProcessMessage.Create("openFileRequest");
msg.Arguments.SetInt(0, (int)promiseId);
// This kicks off the RFC chain.
frame.SendProcessMessage(CefProcessId.Browser, msg);
}
protected override void DoAsyncWork(CefV8Context ctx, PromiseTask promiseTask)
{
// Start running C# code in its own thread, no JS calls are allowed at this point.
Task.Run(() =>
{
try
{
var result = promiseWorker.Method.Invoke(promiseWorker.Target, callerArguments);
promiseTask.Resolve(result);
}
catch (Exception ex)
{
promiseTask.Reject(ex);
}
});
}
/// <summary>
/// Start executing the promise worker on a thread pool thread.
/// </summary>
/// <param name="arguments">The two callback provided by the JS side, one for resolving
/// and one for rejecting the JS Promise.
/// </param>
protected override bool Execute(string name, CefV8Value obj, CefV8Value[] arguments, out CefV8Value returnValue, out string exception)
{
var resolveCb = arguments[0];
var rejectCb = arguments[1];
var ctx = CefV8Context.GetCurrentContext();
var promiseTask = new PromiseTask(ctx, resolveCb, rejectCb);
DoAsyncWork(ctx, promiseTask);
// A fulfiller function doesn't return anything -- it's equivalent to
// a 'void' C# function, so return 'undefined' to JS side.
returnValue = CefV8Value.CreateUndefined();
exception = null !;
return(true);
}
protected abstract void DoAsyncWork(CefV8Context ctx, PromiseTask promiseTask);
